SHANGHAI: A major cricket gambling den with more than 200 gamblers and 1.8 million yuan (US$220,000) in wagers was recently shut down in Shanghai.

Reports from residents last month led authorities to the operation in a deserted factory building in Huaxin Town of Qiangpu District, said Zhuang Wei, an official with the Shanghai Municipal Public Security Bureau.

"This is a well-organized gang with clear division of work - they have specific staff to pick up gamblers through the city, arrange the facilities, and work as judges," Zhuang said.

Thirty-six people are in custody following the bust.

The gang started organizing cricket gambling in October, and constantly shifted their base of operation, Zhuang said.

"In addition, they controlled the gambling by feeding drugs to crickets before the fight."

Men in their 40s and 50s made up more than 60 per cent of all gamblers, said Zhuang.

It is said that the smallest bet was set at 5,000 yuan (US$600).

Cricket fighting is a seasonal gambling event. It usually starts in summer and lasts until late winter.

Since August, the bureau has included cricket fights as one of the focuses of its gambling crackdown.

By the end of October, the bureau had cracked down on 17,478 gambling activities involving approximate 57,000 gamblers.